S
M
T
W
T
F
S
30
80°
43°
31
79°
42°
1
79°
44°
2
80°
43°
3
79°
41°
4
78°
42°
5
77°
40°
6
78°
42°
7
79°
39°
8
77°
42°
9
78°
42°
10
79°
41°
11
77°
40°
12
76°
40°
13
77°
41°
14
79°
42°
15
82°
45°
16
83°
46°
17
83°
39°
18
81°
36°
19
73°
36°
20
77°
42°
21
81°
43°
22
82°
34°
23
73°
34°
24
72°
33°
25
75°
36°
26
78°
38°
27
Hist. Avg.
75°
41°
28
Hist. Avg.
75°
41°
29
Hist. Avg.
74°
40°
30
Hist. Avg.
74°
40°
1
Hist. Avg.
73°
40°
2
Hist. Avg.
73°
39°
3
Hist. Avg.
73°
39°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Charleston
Charleston's September 2026 forecast shows daily high temperatures ranging from 72° to 83°, with overnight lows between 33° and 46°. The average high for September is 78° with an average low of 40°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how September weather will actually feel in Charleston. See also: October | November | December.
